Chevrolet Full Size Cars 1979-1989

Diesel Fuel Filter


The diesel fuel filter is mounted on the rear of the intake manifold, and is larger than that on a gasoline engine because diesel fuel generally is dirtier (has more suspended particles than gasoline).

The diesel fuel filter should be changed every 30,000 miles or two years.


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Fig. Fig. 1 Diesel fuel filter and lines

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Fig. Fig. 2 HDCA solenoid connection diesel engines

  1. Disconnect the negative battery cable.
  3. With the engine cool, place absorbent rags underneath the fuel line fittings at the filter.
  5. Disconnect the fuel lines from the filter. If possible, use a backup wrench to prevent overtorquing and damaging the fuel lines.
  7. Loosen the fasteners and remove the filter from its bracket.

To install:

  1. Position a new filter to the bracket and secure.
  3. Connect the fuel lines to the fittings being careful nut to overtorque or damage the lines.
  5. Connect the negative battery cable, then start the engine and check for leaks. Run the engine for about two minutes, then shut the engine off for the same amount of time to allow any trapped air in the injection system to bleed off.

GM diesel cars also have a fuel filter inside the fuel tank which is maintenance-free.

If the filter element ever becomes clogged, the engine will stop. This stoppage is usually preceded by a hesitation or sluggish running. General Motors recommends that after changing the diesel fuel filter, the Housing Pressure Cold Advance be activated manually, if the engine temperature is about 125°F. Activating the H.P.C.A. will reduce engine cranking time. To activate the H.P.C.A. solenoid, disconnect the two lead connector at the engine temperature switch and bridge the connector with a jumper. After the engine is running, remove the jumper and reconnect the connector to the engine temperature switch. When the new filter element is installed, start the engine and check for leaks.